Papers by Author: Xiao Yu Zhao

Abstract: Home care is the elderly to continue living in the ordinary residential. The safe communities for elderly concept was proposed and formally developed, which was defined as a community that has established a set of organizational structures and procedures, this paper discuss the environment design methods of community suitable for elderly living including building design.

Abstract: This paper proposes a genetic algorithm to generate and optimize assembly sequences for compliant assemblies. An assembly modeling is presented to describe the geometry of the assembly, which includes three sets of parts, relationships and joints among the parts. Based on the assembly modeling, an assembly sequence is denoted as an individual, which is assigned an evaluation function that consists of the fitness and constraint functions. The fitness function is used to evaluate feasible sequences; in addition, the constraint function is employed to evolve unfeasible sequences. The genetic algorithm starts with a randomly initial population of chromosomes, evolves new populations by using reproduction, crossover and mutation operations, and terminates until acceptable sequences output. Finally an auto-body side assembly is used to illustrate the algorithm of assembly sequence generation and optimization.

Abstract: Dimensional tolerance is an important factor for the geometry quality of products. The stiffness matrices of sheet metal components are usually not variational during the process of tolerance analysis; however, material properties of the compliant parts may change in volume production. The variation of the part thickness changes the part stiffness matrix so that the sensitivity matrix is different from that of the assembly with nominal thickness. The paper proposes an improved sensitivity matrix between the incoming part variation and the assembly variation for the assembly with thickness variation. Moreover, the orthogonal design is used to judge the importance of part and thickness variation for the assembly deviation. The proposed method is illustrated through a case study and the results show that the thickness variation influences the relationship between the part variation and the assembly variation. In addition, part variation plays a more important role to assembly variation than the thickness deviation does according to the orthogonal design.

Abstract: This paper searched a way in order to solve relations between the structures and locking performances for vehicle safety-belt retractor, introduced the emergency locking retractor operating principles, including roll-up mechanism, bearing-strength mechanism, sensitive locking organization. Established the movement equations include the car-body which accelerates, the car-body lean and the pull out strap which accelerates, according to the equations of motion may the design performance parameters and structure parameters. Based on above research, applying MSC.ADAMS to dynamic simulation analysis, to make a analysis between the turn angle of strap-shaft and time, provided a check mean for improving performance of retractor, so as to accord the compulsorily standard ECE. R16: uniform provisions concerning the approval of safety-straps, restraint systems, child restraint systems and ISO fix child restraint systems for occupants of power-driven vehicles and GB14166-2003: safety strap and locking system used for adult passengers of vehicle.

Abstract: A particle swarm algorithm is proposed to generate optimal assembly sequences for compliant assemblies. Firstly, the liaison graph and the adjacency matrix describe the geometry of the compliant assemblies. An assembly sequence is represented by a character string, whose length is the number of all parts. The conceptual tolerance analysis is used to evaluate feasible sequences. Thereafter, the particle swarm algorithm is presented to generate assembly sequences, in which the elite ratio is applied to improve optimization results. Finally a fender assembly is used to illustrate the algorithm of assembly sequence generation and optimization.